Let me state up front that I truly understand what you are saying about the loneliness -- the pain and the anguish of having a hole in one's life following the loss of one's spouse. Of that I am certain we all understand and commiserate. But taking that to the point where you feel you need someone else just to feel whole -- that is a danger sign.
I am concerned for you because this may indicate a diminishment in your own self-worth.
Snow, you are a beautiful child of God, as each and every one of us are. The hard lesson we have to learn is that there is no other human being on the face of the Earth that we need to be whole. The only being we need to complete ourselves is God Himself -- and without that Relationship (big "R", please note) we cannot be complete, not really ...nor can we complete someone else.
I wish I had known that long before now.
So if this is how you are truly feeling, to this degree, then I caution you to please tread lightly. Your H may or may not be sincere in turning a new leaf. But either way you are very vulnerable right now.